4. Stuff the turkey with celery, carrots, and onions. Place some celery, carrot, and onion pieces in the roasting pan around the turkey. This step is optional.
6. After the 30 minutes have passed, lower the oven temperature to 350°F and cover the turkey with aluminum foil. Continue to bake until the turkey reaches a temperature of 165°F, about 3 hours for a 12-pound turkey.